Careful, you have to also add --no-preserve-root to make sure you get all of it out. If you leave the roots, it'll just grow back later!

(But seriously, don't actually do this unless you're prepared to lose data and potentially even brick your computer. Don't even try it on a VM or a computer you're planning to wipe anyway, because if something is mounted that you don't expect, you'll wipe that too. On older Linux kernels, EFI variables were mounted as writable, so running rm -rf / could actually brick your computer. This shouldn't still be the case, but I wouldn't test it, myself.)

I think this article from the Verge explains it pretty well.

tl;dr:

• The Fed kept interest rates low from 2008 to 2021. Low interest rates made it easier to borrow money and meant that debt-backed investments like bonds had a low return, so investors favored stocks for a better yield on their investment.
• This meant tech companies could borrow a ton of money at low interest rates and raise a ton of money from investors through stock sales, allowing them to build services that weren't profitable in order to grow as rapidly as possible. This basically defined the internet as we know it today - big companies offering free/cheap services with minimal restrictions. Companies could afford to charge low fees and look the other way on things like ad blockers.
• However, now that interest rates are going up, borrowing is much more expensive and investors are less motivated to buy stock, so all that easy money has dried up. Companies are having to raise revenue by increasing prices, adding more ads, blocking ad blockers, etc.

Honestly, I should probably set up a system-wide adblocker, but I just use uBlock in Firefox and avoid apps that shove ads in my face.

Could've been UPS using USPS for last-mile delivery. The OP is also from feddit.de so maybe they're not in the US.